General LinuxBIOS Questions

[Eric W Biederman]

We are down to questions that are definitely appropriate for the list.

"Jeffrey B. Layton" <laytonjb at bellsouth.net> writes:

> Eric W Biederman wrote:
> 
> >"Jeffrey B. Layton" <laytonjb at bellsouth.net> writes:
> >
> >
> >>Could you
> >>list some pros and cons for a prospective customer that
> >>is thinking about switching to LinuxBIOS but they are
> >>used to the regular old BIOS?
> >>
> >
> >The quick list.
> >
> >Pros:
> >Better serial console support.
> >Better debuggability.
> >Better manageability.  (You can do everything under Linux)
> >Quick boot times.
> >Has been tested on big (1000 node) clusters.
> >Vendors care about cluster issues.
> >You get the source.
> >
> >Cons:
> >Boots differently.
> >Harder to find people supporting it.
> >
> 
> I've got a question about the serial console support and the better
> manageability. With LinuxBIOS can you put BIOS messages
> across the network to the master node from power on? Or do
> you have to wait until you get to Lilo (and then use something
> like netconsole in the kernel)?

You can do serial from power on.  Over the network is a more
interesting problem, and hasn't been fully solved yet.  Currently I
connect the serial port to a box with a lot of serial ports, and
that box is network accessible.

NIC hardware is noticeably more complex than serial ports so getting
a network console going from power on is still an open issue.  I don't
know that it has been tested much yet.

> As for the manageability issue. How is the cluster more manageable
> with LinuxBIOS (I'm not being argumentative, but rather curious)?
>
> For example, if I have a cluster that's pretty stable where I don't lose
> many nodes and I don't need to change the BIOS at all, then what
> does LinuxBIOS give me in terms of manageability?

Manageability is really about when things fail, and have problems,
not when they work.  But even when things are mostly working
you can set your BIOS options the very first time from Linux, and trust
they are getting set the same as every other node.  You get a reliable
network boot, with etherboot.  You get a fast boot.  You get messages
over the serial console from power on.

Maybe some of these things are only really annoying when the don't
exist and you have lots of hardware.  For me I like the ability
to do a full install including flashing the BIOS on 350 nodes in under
10 minutes. 

But manageability comes down to the fact that the little things are
getting fixed in LinuxBIOS so it is not a pain to work with, after
the learning curve.

Eric